Gun assembly



July 31, 1945. 'MCMULLEN GUN ASSEMBLY Filed Oct. 28, 1945 4 Sheets-Sheet 1 mm 1. max/g IN VEN TOR.

ATTORNEYS July 31, 1945. R. 1.. MOMULLEN 2,380,

GUN ASSEMBLY v I Filed Oct. 28, 194; 4 Sheets-Sheet 2 INVENTOR. E14!!! 1. ft vJ/eq BY v 6 P w-11 A TTORNE Y5 July 31, 1945.

R. L. MCMULLEN GUN AS SEMBLY Filed Oct. 28, 1943 4 Sheets-Sheet 3 MM mm A TTORNE Y5 July 31, 1945. R. L. McMULLEN GUN AS SEMBLY Filed Oct. 28, 1943 4 Sheets-Sheet 4 J0 BY ATTORNEYS -companying drawings, in which Patented July 31, 1945 GUN ASSEMBLY Robert L. McMullen, Trenton, N. J., assignor to Kaiser Cargo, Ina, Bristol, Pa., a corporation of California Application October 28, 1943, Serial No. 507,943

Claims.

This invention relates to fixed gun installations and particularly to improvements designed to permit compact installation of machine and other guns in the wings of airplanes. Such improvements may be desirable in mounting guns in other structures, and the following description, though directed particularly to airplane mountings, is intended as an illustration of the gen eral utility of the structure.

In the customary installation of 50 calibre machine guns in the wings of airplanes, the gun is pivoted on a center support rearwardly of the leading edge of the wing, which is provided with an opening substantially larger than the diameter of the muzzle to permit necessary adjustment of the gun to, alignment with the desired direction of fire. Such openings interfere with the aerodynamic characteristics of the leading edge of the wing. Moreover, the openings permit water,

' dirt and other undesirable elements to enter the and necessitatesgcomplicated modification of the internal structure of the wings.

, It is the object of the present invention prothe advantage of arranging the ammunition box parallel to the axis of the gun;

Fig. 3 is an enlarged-sectional view illustrating the mounting for the muzzle of the gun;

Fig. 4 is a section on the line 4-4 of Fig. 3; Fig. 5 is a section on the line 5-5 of Fi 4; Fig. 6 is a sectional view through a conventional airplane wing showing the gun with its vide a gun mounting which avoids the difliculties rately and reliably to the firing chamber.

Other objects and advantages of the invention will be apparent as it is better understood by reference to the following specification and the ac- Fig. 1 is a sectional-view through a conventional airplane wing showing the gun installaand the feeding chute;

Fig. 2 is a diagrammatic plan view illustrating rear support and the ammunition box and chute associated therewith;

Fig. 7 is a plan view of the structure shown in Fig. 6;

Fig. 8 is an enlarged sectional view of the rear support for the gun; and Fig. 9 is a section on the line .99 of Fig. 8. The advantages of the invention are accomplished by supporting the muzzle of the gun in a ball and socket joint mounted on the supporting frame of the wing with an opening in the leading edge of the wing which conforms substantially to the periphery of the outer edge of the opening in the socket to provide a joint which effectively excludes water, dirt and other extraneous material. The muzzle oi the gun has a sliding fit in the opening provided therefor in the ball. Recoil loads are transmitted directly to the ball through struts connected to the gun adjacent the firing chamber and thence to the socket and to the .wing will varyin diil'erenttypes of planes and forms no part of the invention. A brace I, intended to represent conventionally the usual truss structure of a wing, has an opening 8 therein through. which the gun barrel 9 projects. Similarly, members l0 and II indicate conventionally a part of 'the wing frame to which the gun mounting is secured.

The gun 9 may be a standard 50 calibremachine gun or any other type of gun suitable for mounting in airplanes or inother structures. The mechanism for feedin firing and controlling the firing of the gun forms no part of the present invention, and hence is not illustrated and described in detail. Such guns have mechanism actuated by gas pressure or otherwise to efiect the step-by-step movement of the ammunition belt whereby successive rounds of ammunition are introduced to the breech of the gun and fired. The empty shells and links are ejected automatically after each round is fired.

In accordance with the present invention, the

' muzzle of the gun 9 is slidably supported in a ball I2 having trunnions l9.. The latter are disposed in openings in members ll secured to tubular struts II. The rearward ends of the struts are fastened to the gun 9 adjacent the firing chamber I! so that the recoil load is conveyed directly to the 'trunnions I9 and thence to the ball 12. The gun is of a design in which great rearward movement of the barrel is not needed to take up the recoil and onein which the great part of the recoil can be transmitted to the wing structure. The gun can. be, however, of the recoiling barrel type as long as the longitudinal movement of the gun barrel with respect to the ball I2 is small. Only such recoil which is not transmitted to the wing structure is taken up by slidable connection of the gun muzzle with the ball l2.

The ball I2 is enclosed in a socket comprising sections I! and I! having flanges l9 and 20. Bosses 2| are secured to the flanges l9 and the parts are held in assembled relation with flanges 22 of brackets 23 by a plurality of bolts 24. The

muzzle while recoil loads are transmitted to the wing frame. The muzzle may move longitudinally under such recoil loads. The leading edge 9 of the wing has an opening 25 in front of the muzzle of the gun. This opening may be relatively small, since the muzzle moves only about a point adjacent thereto and longitudinally. The socket moreover prevents access of water, dirt and other extraneous material to the gun bay A plug 26 maybe inserted in the opening 25 and may conform to the contour of the leading edge 9. The plug will remain in place until the gun is first fired, thus further protecting the mechanism during ment to the target.

While in the preferred construction the muzzle of the gun terminates within the leading edge of the wing, it may extend through the edge and project for some distance. The pivotal point nevertheless will be adjacent the leading edge and the advantages of the invention will be retained.

'In order to properly align the gun for the desired direction of fire, the rear end thereof is mounted on a bracket 21 having a slot 28 therein which engages a transverse member 29 of theadjusting' mechanism. Owing to themyision of the slot, any recoil load tending to move the gun rearwardly in the direction of its axis is not transmitted to the rear mounting. This mounting comprises a bracket 30 secured by bolts 3| to the members In and l I forming a part of the wing frame structure, The bracket 30 has a depending lug 32 to support the end of a screw 33 having a knurled head 34 whereby the screw may be turned to effect vertical-adjustment of the rear of the gun. A trunnion 35, threadedly mounted on the screw, is carried in a socket I! of a frame 37 which is pivotally supported on the bracket 89 at 38. Movement of the screw 33 causes the frame 3? to tilt on its pivot 38. The member 223 extends transversely of the frame 91 and hence the tilting movement is transmitted to the brooket and to the rear of the gun.

To effect horizontal adjustment of the gun, the

member 29 isi threaded on shaft 99 which is free to rotate but is held in frame 91 and carries a worm 49 at its opposite end engaging a worm wheel 4| on a shaft 42 having a knurled head 43. Adjustment of the shaft 42 effects lateral movement of the member 29 and conveys such movement to the gun'. through the bracket 21. Rotation of the member 29 is prevented by a tongue 4| secured to the member 29 and engaging a slot '45 in an extension, of the frame 31.

When the rear of the gun is adjusted by ma- 7 nipulation of the knurled heads 34 and 49, the gun swings on the pivot adjacent its muzzle and thus may be directed in the desired line of fire. I

The adjustment is limited, since ms of this type are intended tobe directed to a target within a certain range and in alignment with the sights provided for the operator of the plane. The adjustmen'ts are made while the plane is on the ground and are not changed during the operation thereof.

To secure the added advantage of compactness, the ammunition box 41, which may be of standard construction, is disposed parallel to the axis of the gun with its forward end adjacent to the firing chamber. The ammunition box may be fastened in the customary manner to a supporting structure. The ammunition 'belt is likewise of standard structure and it is disposed in the box in the usual manner. To feed the ammunition belt, I provide a chute 49, one end of which is secured to the outlet from the ammunitiombox. The chute as indicated is twisted through an angle of 90. Rollers 50 and 5| provide a reduced friction bearing for the passage of the ammunition belt over the sharpest angles. Slots are provided in the chute through which the rollers 50 and BI engage the'traveling belt. The chute i provided with a flexible section 52 in order that slight movement of the gun due to recoil and adjustment may not afiect its proper alignment, The end of the chute 53 is secured to the gun at the point where the ammunition belt normally enters it. Practical operation has demonstrated that the ammunition belt/may be fed successfully to the gun through a chute as described without danger of blocking'or other mishap. When the ammunition box is installed, the belt is threaded through a chute with the first round in firing position. When the gun is fired, the belt automatically advances to feed the ammunitionasrequired.

As indicated in Fig. 2 of the drawings, the arrangement described permits the grouping of guns in the limited spa": such aSLiS afi'orded by the wing of an airplane in a much more compact fashion than has been possible heretofore. A greater number of guns may be mounted in a given space. Hence the fire power of an airplane may be increased by the application of the in- .vention as described. It also permits all of the guns to be arranged with their muzzles immediately adjacent the leading edge. The arrangement of the ammunition box parallel to the gun can be employed with gun. mountings diifering and for axial displacement with respect thereto, a rear support having adjustable means thereon to efi'ect the pivotal movement of the gun about its pivotal connecting means and means for connecting the gun to the rear support for axial movement, and strut means attached to the gun rearwardly of the muzzle and to the forward support to receive and transmit the recoil loads of the gun to the front support.

2. A gun assembly comprising a gun, a forward support, means for connecting the muzzle of the gun for pivotal movement of the gun about a point adjacent to the muzzle, said connecting means including a socket and a ball slidably receiving the gun muzzle and cooperating with the socket, a rear support having adjustable means thereon to effect the pivotal movement of the gun and a slidable connection for connecting. the gun to the rear support to provide for axial movement of the gun with respect thereto, and strut means attached to the gun rearwardly of the muzzle and to the forward support to receive and to transmit the recoil loads of the'gun to the front support.

3. A gun assembly comprising a gun having a ball slidably mounted thereon, a socket co-operating with the-ball and secured to a bracket, recoil load struts at opposite sides of the gun attached to the ball and to the gun, and a rear support having means for adjusting the direction of fire, said struts serving to transmit the recoil loads of the gun to socket bracket.

4. A gun assembly for airplane wings comprising a, wing structure having an opening in its leading edge, a bracket supported on the wing structure, a socket supported by the bracket, a gun having a ball co-operating with the socket and slidably mounted on the gun adjacent the leading edge of the wing, a rear support having means for pivotall adjusting the gun and means for connecting the gunto the rear support for axial displacement with respect thereto and means attached to the gun and to the ball to transmit the recoil loads to the bracket.

5. A gun assembly for airplane wings comprising a wing structure having an opening in its leading edge, a bracket supported on the wing structure, a socket supported by the bracket and having an opening, a gun having a ball co-opcrating with the socket and having an opening and slidably mounted on the gun adjacent the leading edge of the wing, a rear support having means for adjusting the gun and means for connecting the gun to the rear support for axial movement with respect thereto, means attached to the gun to transmit the recoil loads to the bracket and a removable plug conforming to the leading edge and extending into the socket opening to close the muzzle opening until the gun is fired. t ROBERT L. MoMULLEN. 

